1998 Rover 4 Series Starting and rattling noise

I went on a trip that was 500 miles.
The next day when I tried to start the car, I had to do it twice before it would start. I had all the fluids changed and/or checked and topped up. EZ Lube said it all looked good including alternator and battery - maybe it was bad gas. I got some fuel injector cleaner and better gas and it started immediately. But then when I got it home, I had to try it 2 or 3 times to make it catch again.

At the same time a slight tinny rattle developed that has gotten worse over 24 to 48 hours. It sounds like it comes from the exhaust or the sides of the car.